GTM21 plug wiring - help please

[inspiredron]

For some time the cable on my GTM21 has been working its way out of the plug despite my attempts to araldite the cable grommet to the plug itself. Now, although the unit charges my 660FM, the traffic has ceased working. I have dismantled the plug and found two wires had become detached - red and purple. Would anyone be willing to open the plug on their GTM21 and tell me the order of the colours on the plug?
I am currently getting a message that the serial device needs power which is consistent with at least one wire being off.
Any help would be very appreciated.

I notice that the GTM25 is much cheaper than the GTM21. Does anybody know if that will charge and do traffic for the 660FM via the mini usb socket instead of powering via the windscreen mount as with the GTM21?

[PhilHornby]

[inspiredron]

Many thanks for your response, Phil. I tend to forget about GPS Passion!

I found a diagram and explanation on this post
http://www.gpspassion.com/forumsen/topic.asp?TOPIC_ID=91718&whichpage=13
which matches the wiring on my GTM21 even though it is labelled as the GTM20.
The plug is a bit odd as it has 9 pins but only 7 solder points and some printed circuitry that goes between the pins and the solder points. The colours and pins on my GTM21 match precisely this map given that 1&2 and 8&9 are internally connected. My order is red, purple, yellow, blue, black, green, and brown.
When I took the plug apart both red and purple were disconnected and I resoldered both. I am guessing, as purple takes power out to the traffic, that I did not make a good job or resoldering the purple wire. Guess I'd better try again. I will post again if I get it working.
Thanks again
Ron
PS I cannot remember if I can post pictures here. If so I could post low res copies of a photo of the plug and the diagram.

[inspiredron]

An update!
I sent a support request to Garmin and had a quick response that the GTM25 will not work with the nuvi 660FM. They also added that my dead GTM21 has value and that they will do an RMA for £16.66 as the unit is out of warranty. That's a bargain and I have paid the cost and am returning the unit for replacement.
Full marks to Garmin!

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